murmuring
1. [ noun ] a low continuous indistinct sound; often accompanied by movement of the lips without the production of articulate speech
Synonyms: murmur muttering murmuration mussitation mutter
Related terms: sound mumble murmur
2. [ adjective ] making a low continuous indistinct sound
Synonyms: whispering susurrant
Examples:

"like murmuring waves" "susurrant voices"

Related terms: soft
3. [ noun ] a complaint uttered in a low and indistinct tone
Synonyms: grumbling mutter murmur muttering grumble
Related terms: complaint murmur
Similar spelling:   murmur
  murmuration
  murmurous